The inexpensive GM22 Geiger Counter Kit is sensitive to beta and gamma rays and uses a glass SI-39 geiger mueller tube. It easily detects with clicks and flashes of red light all types of radioactive minerals, radioactive isotopes, radioactive orange plates, old radium watch hands, old lantern mantles, larger vaseline glass objects, cosmic rays from space and of course radioactive contamination. Operates from one 9V battery (not included). Size of PC board is 1.3" x 4.1". Background radiation in Arizona measured with this kit is about 8 to 10 counts per minute. Complete with all parts, SI-39 glass geiger mueller tube, PC board and instructions.
Skill level 2. No case available.